An upload callback refers to the process in which the client includes a callback parameter in its request. Upon completion of the upload, the server sends a synchronous POST callback request to the third-party application server specified in the callback. Only after the third-party application server confirms receipt and returns a result are all results returned to the client.

For a detailed introduction to upload callback, please refer to Upload Callback.

Sample Code

Implementation of upload callback for standard upload

using System;​
using System.IO;​
using System.Text;​
using TOS;​
using TOS.Error;​
using TOS.Model;​
​
namespace TestTos​
{​
    internal class Program​
    {​
        private static void Main(string[] args)​
        {​
            var ak = Environment.GetEnvironmentVariable("TOS_ACCESS_KEY");​
            var sk = Environment.GetEnvironmentVariable("TOS_SECRET_KEY");​
            var endpoint = "https://tos-cn-beijing.volces.com";​
            var region = "cn-beijing";​
            var bucketName = "*** Provide your bucket name ***";​
            var objectContent = "Hello TOS";​
            var objectKey = "example_dir/example.txt";​
            var callback = "your callback param";​
            var callbackVar = "your callback custom variable";​
            ​
            var client = TosClientBuilder.Builder().SetAk(ak).SetSk(sk).SetEndpoint(endpoint).SetRegion(region).Build();​
​
            try​
            {​
                byte[] binaryData = Encoding.UTF8.GetBytes(objectContent);​
                using (MemoryStream requestContent = new MemoryStream(binaryData))​
                {​
                    var putObjectInput = new PutObjectInput()​
                    {​
                        Bucket = bucketName,​
                        Key = objectKey,​
                        Content = requestContent,​
                        Callback = Convert.ToBase64String(Encoding.UTF8.GetBytes(callback)),​
                        CallbackVar = Convert.ToBase64String(Encoding.UTF8.GetBytes(callbackVar))​
                    };​
                    var putObjectOutput = client.PutObject(putObjectInput);​
                    Console.WriteLine("Put object succeeded, ETag: {0} ", putObjectOutput.ETag);​
                    Console.WriteLine("Put object succeeded, CallbackResult: {0} ", putObjectOutput.CallbackResult);​
                }​
            }​
            catch (TosServerException ex)​
            {​
                Console.WriteLine("Put object failed, request id {0}", ex.RequestID);​
                Console.WriteLine("Put object failed, status code {0}", ex.StatusCode);​
                Console.WriteLine("Put object failed, response error code {0}", ex.Code);​
                Console.WriteLine("Put object failed, response error message {0}", ex.Message);​
            }​
            catch (TosClientException ex)​
            {​
                Console.WriteLine("Put object failed, error message {0}", ex.Message);​
            }​
            catch (Exception ex)​
            {​
                Console.WriteLine("Put object failed, {0}", ex.Message);​
            }​
        }​
    }​
}​

Implementation of Callback Mechanism for Multipart Uploads

using System;​
using System.Collections.Generic;​
using System.IO;​
using System.Text;​
using TOS;​
using TOS.Error;​
using TOS.Model;​
​
namespace ConsoleApp​
{​
    internal class Program​
    {​
        private static void Main(string[] args)​
        {​
            var ak = Environment.GetEnvironmentVariable("TOS_ACCESS_KEY");​
            var sk = Environment.GetEnvironmentVariable("TOS_SECRET_KEY");​
            var endpoint = "https://tos-cn-beijing.volces.com";​
            var region = "cn-beijing";​
            var bucketName = "*** Provide your bucket name ***";​
            var objectKey = "example_dir/example.txt";​
            var localFileName = "/usr/local/test.txt";​
            var callback = "your callback param";​
            var callbackVar = "your callback custom variable";​
​
            var client = TosClientBuilder.Builder().SetAk(ak).SetSk(sk).SetEndpoint(endpoint).SetRegion(region).Build();​
​
            var uploadID = "";​
            try​
            {​
                var createMultipartUploadInput = new CreateMultipartUploadInput​
                {​
                    Bucket = bucketName,​
                    Key = objectKey,​
                    ACL = ACLType.ACLPrivate,​
                    StorageClass = StorageClassType.StorageClassIa,​
                    Meta = new Dictionary<string, string> { { "key", "value" } }​
                };​
                var createMultipartUploadOutput = client.CreateMultipartUpload(createMultipartUploadInput);​
                uploadID = createMultipartUploadOutput.UploadID;​
                Console.WriteLine("CreateMultipartUpload succeeded, request id {0}",​
                    createMultipartUploadOutput.RequestID);​
                Console.WriteLine("CreateMultipartUpload succeeded, upload id {0}", uploadID);​
            }​
            catch (TosServerException ex)​
            {​
                Console.WriteLine("CreateMultipartUpload failed, request id {0}", ex.RequestID);​
                Console.WriteLine("CreateMultipartUpload failed, status code {0}", ex.StatusCode);​
                Console.WriteLine("CreateMultipartUpload failed, response error code {0}", ex.Code);​
                Console.WriteLine("CreateMultipartUpload failed, response error message {0}", ex.Message);​
            }​
            catch (TosClientException ex)​
            {​
                Console.WriteLine("CreateMultipartUpload failed, error message {0}", ex.Message);​
            }​
            catch (Exception ex)​
            {​
                Console.WriteLine("CreateMultipartUpload failed, {0}", ex.Message);​
            }​
​
            long partSize = 20 * 1024 * 1024;​
            var fi = new FileInfo(localFileName);​
            var fileSize = fi.Length;​
            var partCount = fileSize / partSize;​
            if (fileSize % partSize != 0) partCount++;​
            var parts = new UploadedPart[partCount];​
​
            try​
            {​
                using (var fileStream = File.Open(localFileName, FileMode.Open, FileAccess.Read))​
                {​
                    for (var i = 0; i < partCount; i++)​
                    {​
                        var offset = partSize * i;​
                        fileStream.Seek(offset, 0);​
                        var contentSize = partSize < fileSize - offset ? partSize : fileSize - offset;​
                        var UploadPartInput = new UploadPartInput​
                        {​
                            Bucket = bucketName,​
                            Key = objectKey,​
                            UploadID = uploadID,​
                            PartNumber = i + 1,​
                            Content = fileStream,​
                            ContentLength = contentSize​
                        };​
                        var uploadPartOutput = client.UploadPart(UploadPartInput);​
                        parts[i] = new UploadedPart { PartNumber = i + 1, ETag = uploadPartOutput.ETag };​
                        Console.WriteLine("UploadPart succeeded, request id {0}", uploadPartOutput.RequestID);​
                    }​
                }​
            }​
            catch (TosServerException ex)​
            {​
                Console.WriteLine("UploadPart failed, request id {0}", ex.RequestID);​
                Console.WriteLine("UploadPart failed, status code {0}", ex.StatusCode);​
                Console.WriteLine("UploadPart failed, response error code {0}", ex.Code);​
                Console.WriteLine("UploadPart failed, response error message {0}", ex.Message);​
            }​
            catch (TosClientException ex)​
            {​
                Console.WriteLine("UploadPart failed, error message {0}", ex.Message);​
            }​
            catch (Exception ex)​
            {​
                Console.WriteLine("UploadPart failed, {0}", ex.Message);​
            }​
​
            try​
            {​
                var completeMultipartUploadInput = new CompleteMultipartUploadInput​
                {​
                    Bucket = bucketName,​
                    Key = objectKey,​
                    UploadID = uploadID,​
                    Parts = parts,​
                    Callback = Convert.ToBase64String(Encoding.UTF8.GetBytes(callback)),​
                    CallbackVar = Convert.ToBase64String(Encoding.UTF8.GetBytes(callbackVar))​
                };​
                var completeMultipartUploadOutput = client.CompleteMultipartUpload(completeMultipartUploadInput);​
                Console.WriteLine("CompleteMultipartUpload succeeded, request id {0}", completeMultipartUploadOutput.RequestID);​
                Console.WriteLine("CompleteMultipartUpload succeeded, callback result {0}", completeMultipartUploadOutput.CallbackResult);​
            }​
            catch (TosServerException ex)​
            {​
                Console.WriteLine("CompleteMultipartUpload failed, request id {0}", ex.RequestID);​
                Console.WriteLine("CompleteMultipartUpload failed, status code {0}", ex.StatusCode);​
                Console.WriteLine("CompleteMultipartUpload failed, response error code {0}", ex.Code);​
                Console.WriteLine("CompleteMultipartUpload failed, response error message {0}", ex.Message);​
            }​
            catch (TosClientException ex)​
            {​
                Console.WriteLine("CompleteMultipartUpload failed, error message {0}", ex.Message);​
            }​
            catch (Exception ex)​
            {​
                Console.WriteLine("CompleteMultipartUpload failed, {0}", ex.Message);​
            }​
        }​
    }​
}​

Last updated: 2025.09.23 11:28:05

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